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Bought a used 1995 Peterbilt 379. Last owner said no issues…

Bought a used 1995...

Bought a used 1995 Peterbilt 379. Last owner said no issues with headlights. Just got it shipped to me. Turn on headlights dash says low beam is on. Passengers low beam is bright and on drivers side low beam is on but dim and drivers side high beam is on a little . Try to switch to high beam nothing changes. Go out front take drivers side high beam bulb out low beam goes out. All the while passengers side low beam never changes.

Mechanic's Assistant: What's the make/model/year of your truck? Engine type?

1995 Pete 379 with an 3406 e motor

Mechanic's Assistant: Anything else you want the truck mechanic to know before I connect you?

Not at the moment Need to figure out lights so I can dot inspect it

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Answered in 1 hour by:
4/11/2019
Technician: Wayne, Journeyman replied 3 years ago
Wayne
Wayne, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 17,969
Experience: worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling
Verified

Hi, I'm Wayne.

I'll be assisting you with this issue today.

Thank you for coming to Just Answer

Your Question is as important to us as it is to you.

Just Answer might prompt you for a phone call,

that request is not from me and is not necessary.

What you are describing is a poor ground either at the headlight or the wire harness.

Check the harness at the corner of the hood for rub marks and bare spots.

I hope this helps you.

Wayne

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Customer reply replied 3 years ago
Ok so a bad ground will mess up the lights but will it prevent low beam switch from switching to high beam
Technician: Wayne, Journeyman replied 3 years ago

Hi,

Thank you for the response.

Sorry, my fault I missed that. I was concentrating on the low beam and dim bulb.

That is a switch issue and also causing the dim light.

I suggest replacing the switch.

Wayne

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Technician: Wayne, Journeyman replied 3 years ago

Hi

Disregard the engine question.

I posted to the wrong question.

Wayne

Wayne
Wayne, Journeyman
Category: Medium and Heavy Trucks
Satisfied Customers: 17,969
Experience: worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling
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Wayne and 87 other Medium and Heavy Trucks Specialists are ready to help you
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Technician: Jeremy, Certified Truck/Bus Technician replied 3 years ago
Jeremy
Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 2,756
Experience: ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, Network Engineer specializing in CAN faults, Aftertertreatment, and vehicle communications
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Wayne
Wayne
Wayne, Journeyman
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Satisfied Customers: 17,969
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Experience: worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling

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